KANPUR, India (Reuters) - South Africa are ready to hand India only their third home test series defeat in two decades when the third and final test begins on Friday, captain Graeme Smith said.

The tourists lead 1-0 after crushing India by an innings and 90 runs on a lively pitch in the second test in Ahmedabad, a victory that brought them close to claiming an Asian treble after wins in Pakistan in November and Bangladesh last month.

Victory in India would be the high point of the season so far before the tours of England and Australia later this year, Smith told reporters.

"We've been comfortable throughout the season, whether it has been in Pakistan, Bangladesh or here," he said. "It's just about doing the same things we have shown the whole season.

"We are the team (close to) winning all three series in the sub-continent in one year. It will be a fantastic achievement."

"As a team we have looked for this opportunity for the whole season. We have got a few major tours coming up this season and India is the first of those challenges."

RANKING BOOST

India have been hit by injuries before the Kanpur test with captain Anil Kumble doubtful while batsman Sachin Tendulkar has already been ruled out.

The visitors are thus confident of securing a series win that would enable them to displace India as the world's second-ranked test team behind Australia.

Referring to South Africa's success in India in 2000 and Australia's triumph four years later, Smith said: "How many teams? It's two in 20 years that have won a series in India."

"It just proves how tough it really is.

Smith said his batsmen will be key again, having repeatedly shown their skill to play spin, while their bowlers will prove difficult to face on a dry pitch expected to crumble easily.

Hashim Amla and opener Neil McKenzie struck centuries in the drawn first test while Jacques Kallis and AB de Villiers, who hit 217 not out, reached triple figures in Ahmedabad.

"We're definitely the more confident team going into this test match, definitely the team under less pressure," said Smith.

"India are still the team with more question marks in terms of selection, injuries and their being 1-0 down in the series."

South Africa may consider playing a second spinner by picking Robin Peterson to partner fellow left-arm bowler Paul Harris to counter the spin-friendly pitch.

"Whether we're going with an extra spinner or not, we have the options. We've played the far more determined cricket on this tour," added Smith. "We have shown greater intensity and hunger to win."